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Are you interested by retrograde problems?
Let me first try to define what a retrograde problem is.
Stable position : a position is said stable if no pieces are in a capture position.
A retrograde problem generally start from an unstable position and the goal is to retrograde the position till a stable position but with a unique optimum suite of moves!
A suite of move is optimum (from the highest priority to the lowest) if
1) the number of plies used is minimum
2) the number of pieces added is minimum
3) the number of kings added is minimum

Just an example
The following position is a correct problem with a unique solution in 2 plies, 1 piece added and 0 king added

But this following one is not correct because there are two solutions in 2 plies, 1 piece added and 0 king added

Some problem can be extremely difficult but let me propose some "easy" ones, just to see if you are interested

To answer your first question, yes in each diagram it is white to move (as usual for a problem).
Concerning the five diagrams you already succeed in 3 of them.
For the reader who is not familiar with such problem I will give the complete solution for these 3 diagrams:

Diag.3
White to play
Diag3 solution
Black to play
1...10-15 2.34-29 15x24
The solution needs 3 plies and when you compare the initial and the final diagram you can see that 2 pieces have been added and 0 king have been added. The score is then 3.2.0. I will write this with the six digit number 030200 which is the best (smallest) number you can get.

Yes Ildjarn ... but it is not still the best score, and so the problem is always not solved.
I am fond of retrograde problem because you have to be very imaginative and skillful and, even with a very simple position (only three pieces here!), you can build quite interesting problems.

ildjarn wrote:I like these kind of puzzles, but I doubt many people here would be interested, since you can't complain about the draw margin in these puzzles.

Thank you very much for your answer Ildjarn.
At least with one person interested I can continue proposing such kind of puzzles.
I think it is a good idea to wait some days between each problem. So I will post a new position in 3 or 4 days.
Do you yourself built positions to be retrograde (but not necessarily a problem with a unique solution) ?

As promised I come back here to give you some more retrograde problems

Let me remind you and clarify how to calculate the score?
First of all you count the number of plies : pliesNumber
Then you compare the problem position (i.e. the final position!) and the solution position (i.e. the initial position you have to discover) and you count:
piecesAddedNumber = number of pieces in the solution position - number of pieces in the problem position
kingsAddedNumber = number of kings in the solution position - number of kings in the problem position
The calcultatio is quite simple:
score = (10000 * pliesNumber) + (100 * piecesAddedNumber) + kingsAddedNumber

Note1 : pliesNumber is always at least equal to 1
Note2 : piecesAddedNumber is null or positive
Note3 : kingsAddedNumber can be null, positive or negative

Oops not so easy is it?
#1 :OK
#2 : your proposal is not correct because your start position is not stable. If you put black man on 23 (instead of 28) and you begin by 23-28 then the score is not the best.
#3 herer you can still get a better score!
#4 is more difficult